There are many kinds of tahdig. The most well known is the rice tahdig. There's also potato tahdig which goes well with chicken dishes. If you choose to layer the bottom of the pan with potato slices, cut them evenly and not too thin. Add a dash of salt after layering them, wait for a few minutes till they are a little bit fried then turn them over and pour the rice over the potatoes and follow the same steps as the rice tahdig recipe. There's also the bread tahdig. Any kind of flat bread could be used such as lavash or pita.
Ingredients: Resource from https://turmericsaffron.blogspot.com/2010/01/the-art-of-making-persian-tah-dig.html
2 cups long grain white basmati rice Butter or vegetable oil 1/2 teaspoon powdered saffron dissolved in 4 tablespoons of hot water Salt Water
Preparation:
In a large bowl wash the rice with cool water a few times to get rid of the extra starch. Soak the rice in 8 cups of cool water, add 4 tablespoons of salt and set aside for at least an hour. In a large non-stick pot that has a tight fitting lid, bring 8 cups of water to a rapid boil on medium-high heat. Drain the soaked rice and pour into the boiling water. Bring the water back to a boil on medium-high heat for about 7 minutes or until the grains are long soft on the outside and hard in the center. Drain the rice in a fine mesh strainer and rinse with cool water a few times. Wash the rice pot and return to heat. Add 2 tablespoons of vegetable oil, 2 tablespoons butter and 1 tablespoon of liquid saffron to the bottom of the pot, move the pan in a circular motion or use a wooden spoon to evenly cover the bottom with oil. Remove from heat and with a large spatula return the parboiled rice back into the pot, building it into a pyramid shape away from the sides of the pot.
In order to release the steam make 4-5 holes in the rice with the handle of the wooden spatula. Place the pot back on the stove on medium heat, uncovered. Wait about 7 minutes or until steam starts coming out of the pot. Gently pour 2 tablespoons oil, 1/4 cup water and a tablespoon of saffron over the rice, cover, lower the heat to medium-low and steam the rice for 45-50 minutes. It is very customary to cover the lid with a kitchen towel or 2-3 layers of thick paper towels to prevent the moisture from going back in the pot. Nowadays, there are fabric lid coverings especially made for this purpose in Iran. I do recommend using it for making a perfect tahdig. To serve tahdig first serve the rice on a platter. Gently mix some of the rice with the dissolved saffron and arrange it nicely on top. Remove the tahdig with a spatula and cut into small pieces.